What has given Saarinen's windowless brick cylinder such enduring power is not so much its place in the timeline of architecture as its sheer timelessness. Although it has medieval references, the chapel transcends periods. The architect created, by his own description, a self-contained, inward-feeling' environment. Undulating brick walls serve an acoustic purpose and enhance the atmosphere of 'spiritual unworldliness' the architect sought to achieve. Fifty feet in diameter and 30 feet high, the chapel is topped by a sculptural aluminum spire with an arched bell tower at its base. Saarinen surrounded the chapel with a moat that further insulates the building from the urban landscape. Reflections of sunlight on the rippling water dance across the interior walls of the chapel through irregular arched openings along its base. Pinhole ceiling lights and a large, cylindrical altar light lend to the ethereal atmosphere. A delicate metal sculpture by Harry Bertoia hangs from ceiling to floor behind the altar, enriching the play of light and shadow on the chapel walls.' Source: http://web.mit.edu/evolving/projects/chapel/